dup2

creatory

/*Redirect STDOUT_FILENO to a file*/
#include
#include
#include
#include
#include
#include
#include
#define BUF_SIZE 1024
int main(int argc,char **argv)
{
char buffer[BUF_SIZE];
int fd;
if(argc!=2)
{
fprintf(stderr,"Usage:%s filename\n",argv[0]);
return 0;
}
/*create the dest file*/
if((fd=open(argv[1],O_WRONLY|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR))==-1)
{
fprintf(stderr,"create file [%s] failed:[%s]\n",argv[1],strerror(errno));
return 0;
}
/*redirect*/
if(dup2(fd,STDOUT_FILENO)==-1)
{
fprintf(stderr,"Redirect Standard Out Error:[%s]\n",strerror(errno));
close(fd);
exit(0);
}
fprintf(stderr,"Now,Please input the content.");
fprintf(stderr,"To quit use CTRL+D\n");
while(1)
{
memset(buffer,0,BUF_SIZE);
fgets(buffer,BUF_SIZE,stdin);
if(feof(stdin)) break;
write(STDOUT_FILENO,buffer,strlen(buffer));
}
return 0;
}


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